Automatic document feeder having detachable sheet-pressing slice

ABSTRACT

The present invention provides an automatic document feeder having a detachable sheet-pressing slice. The automatic document feeder is mounted on a scanning apparatus having a scanning window. By means of the automatic document feeder, multiple documents are successively transported across the scanning window of the scanning apparatus to perform the scanning operation. The automatic document feeder includes a casing and a sheet-feeding mechanism. The detachable sheet-pressing slice is disposed at a lower part of the sheet-feeding mechanism. In a case that the detachable sheet-pressing slice is damaged, only the detachable sheet-pressing slice needs to be detached from the automatic document feeder and replaced with a new one. As a consequence, the maintenance of the detachable sheet-pressing slice is very easy and speedy.

FIELD OF THE INVENTION

The present invention relates to an automatic document feeder, and moreparticularly to an automatic document feeder having a detachablesheet-pressing slice.

BACKGROUND OF THE INVENTION

Scanning apparatuses are commonly used for scanning for example papersheets. The scanned images can be converted into digital electronicfiles, which are then stored in a computer. Conventionally, for scanningseveral paper sheets, the paper sheets should be manually fed into thescanning apparatus one by one. This means of manually feeding the papersheets is time-consuming and laboring. Nowadays, the scanning apparatususually has an automatic document feeder for successively andcontinuously feeding many paper sheets. After a stack of papers to bescanned are placed on the sheet input tray of the automatic documentfeeder, the sheet-feeding mechanism of the automatic document feederwill successively transport the paper sheets across the scanning windowof the scanning apparatus to perform the scanning operation.

FIG. 1 is a schematic cross-sectional view of an automatic documentfeeder for use with a scanning apparatus. The automatic document feeder1 principally includes a casing 10 and a sheet-feeding mechanism 11inside the casing 10. In addition, the casing 10 includes a sheet inputtray 101 and a sheet ejecting tray 102. The scanning apparatus 4includes a scanning window 40 and a scanning module 41 under thescanning window 40.

Please refer to FIG. 1 again. In the automatic document feeder 1, thesheet input tray 101 is used for placing thereon the documents S to bescanned by the scanning apparatus 4. By means of the sheet-feedingmechanism 11, the documents S supported on the sheet input tray 101 aresuccessively fed into the sheet transfer path of the automatic documentfeeder 1. When each of the documents S is transported across thescanning window 40 of the scanning apparatus 4, the image thereof isscanned by the scanning module 41 under the scanning window 40. Afterthe scanning operation is implemented, the document S is ejected by thesheet-feeding mechanism 11 to the sheet ejecting tray 102.

Please refer to FIG. 1 again. Generally, the document S is readily bentupwardly when passing through the scanning window 40 of the scanningapparatus 4. The bent portion may adversely affect the scanning qualityof the scanning apparatus 4. For preventing the bent portion of thedocument S from rising up, the lower part of the sheet-feeding mechanism11 of the automatic document feeder 1 further includes a sheet-pressingslice 12 at around the scanning window 40 of the scanning apparatus 4.Since the document S passing through the scanning window 40 is pressedby the sheet-pressing slice 12 to lie flat on the scanning window 40,the scanning quality of the scanning apparatus 4 is enhanced.

Since the sheet-pressing slice 12 is mounted and fixed on the lower partof the automatic document feeder 1, there are still some drawbacks. Forexample, if the sheet-pressing slice 12 is damaged, the wholesheet-feeding mechanism 11 should be detached from the automaticdocument feeder 1 to replace the sheet-pressing slice 12 with a new one.Therefore, the maintenance of the automatic document feeder 1 iscomplicated.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an automaticdocument feeder having a detachable sheet-pressing slice on a lower partof the automatic document feeder, in which the sheet-pressing slice isdetachable and replaceable to be easily refreshed in order to overcomethe problem of refreshing the fixed sheet-pressing slice in the priorart.

In accordance with an aspect of the present invention, there is providedan automatic document feeder having a detachable sheet-pressing slice.The automatic document feeder is mounted on a scanning apparatus havinga scanning window. By means of the automatic document feeder, multipledocuments are successively transported across the scanning window of thescanning apparatus to perform the scanning operation. The automaticdocument feeder includes a casing and a sheet-feeding mechanism. Thedetachable sheet-pressing slice is disposed at a lower part of thesheet-feeding mechanism and around the scanning window for pressing thedocument passing through the scanning window.

In an embodiment, a retaining recess is further formed at the lower partof the sheet-feeding mechanism for receiving the detachablesheet-pressing slice therein.

In an embodiment, the detachable sheet-pressing slice includes a fixingmember and a sheet-pressing member.

In an embodiment, a hook structure is protruded from an inner wall ofthe retaining recess, and a concave structure is formed in the fixingmember, wherein the detachable sheet-pressing slice is fixed on thelower part of the sheet-feeding mechanism when the detachablesheet-pressing slice is inserted into the retaining recess and the hookstructure and the concave structure are engaged with each other.

In an embodiment, an ejecting hole is further formed at the lower partof the sheet-feeding mechanism for allowing a sharp-pointed stick topenetrate therethrough and push the fixing member, thereby disengagingthe hook structure from the concave structure.

In an embodiment, a concave structure is formed in an inner wall of theretaining recess, and a hook structure is protruded from the fixingmember, wherein the detachable sheet-pressing slice is fixed on thelower part of the sheet-feeding mechanism when the detachablesheet-pressing slice is inserted into the retaining recess and the hookstructure and the concave structure are engaged with each other.

In an embodiment, an ejecting hole is further formed at the lower partof the sheet-feeding mechanism for allowing a sharp-pointed stick topenetrate therethrough and push the fixing member, thereby disengagingthe hook structure from the concave structure.

In an embodiment, the detachable sheet-pressing slice is asheet-pressing member with a concave structure.

In an embodiment, a hook structure is protruded from an inner wall ofthe retaining recess, and the detachable sheet-pressing slice is fixedon the lower part of the sheet-feeding mechanism when the detachablesheet-pressing slice is inserted into the retaining recess and the hookstructure and the concave structure are engaged with each other.

In an embodiment, an ejecting hole is further formed at the lower partof the sheet-feeding mechanism for allowing a sharp-pointed stick topenetrate therethrough and push the fixing member, thereby disengagingthe hook structure from the concave structure.

In an embodiment, the detachable sheet-pressing slice further one ormore salient structures to be sustained against an inner wall of theretaining recess.

The above objects and advantages of the present invention will becomemore readily apparent to those ordinarily skilled in the art afterreviewing the following detailed description and accompanying drawings,in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of an automatic documentfeeder for use with a scanning apparatus;

FIG. 2 is a schematic cross-sectional view of an automatic documentfeeder having a detachable sheet-pressing slice according to a preferredembodiment of the present invention;

FIG. 3A is a schematic partial enlarged cross-sectional view of theautomatic document feeder of FIG. 2, in which the detachablesheet-pressing slice has been mounted on the lower part of thesheet-feeding mechanism;

FIG. 3B is a schematic partial enlarged cross-sectional view of theautomatic document feeder of FIG. 2, in which the detachablesheet-pressing slice is separated from the automatic document feeder;

FIG. 3C is a schematic partial enlarged cross-sectional view of theautomatic document feeder of FIG. 2, in which a sharp-pointed stick isused to disengage the detachable sheet-pressing slice;

FIG. 3D is a schematic partial enlarged cross-sectional viewillustrating another engagement between the retaining recess and thefixing member of the detachable sheet-pressing slice;

FIG. 4A is a schematic partial enlarged cross-sectional viewillustrating an automatic document feeder according to a secondembodiment of the present invention; and

FIG. 4B is a schematic partial enlarged cross-sectional viewillustrating an automatic document feeder having another detachablesheet-pressing slice.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 2 is a schematic cross-sectional view of an automatic documentfeeder having a detachable sheet-pressing slice according to a preferredembodiment of the present invention. The automatic document feeder 2 ismounted on a scanning apparatus 4. The automatic document feeder 2principally includes a casing 20 and a sheet-feeding mechanism 21 insidethe casing 20. In addition, the casing 20 includes a sheet input tray201 and a sheet ejecting tray 202. The scanning apparatus 4 includes ascanning window 40 and a scanning module 41 under the scanning window40.

Please refer to FIG. 2 again. In the automatic document feeder 2, thesheet input tray 201 is used for placing thereon the documents S to bescanned by the scanning apparatus 4. By means of the sheet-feedingmechanism 21, the documents S supported on the sheet input tray 201 aresuccessively fed into the sheet transfer path of the automatic documentfeeder 2. When each of the documents S is transported across thescanning window 40 of the scanning apparatus 4, the image thereof isscanned by the scanning module 41 under the scanning window 40. Afterthe scanning operation is implemented, the document S is ejected by thesheet-feeding mechanism 21 to the sheet ejecting tray 202.

Please refer to FIG. 2 again. For preventing the document S from risingup when passing through the scanning window 40 of the scanning apparatus4 without impairing the scanning quality of the scanning apparatus 4,the lower part of the sheet-feeding mechanism 21 of the automaticdocument feeder 2 further includes a detachable sheet-pressing slice 22at around the scanning window 40 of the scanning apparatus 4. Since thedocument S passing through the scanning window 40 is pressed by thedetachable sheet-pressing slice 22 to lie flat on the scanning window40, the scanning quality of the scanning apparatus 4 is enhanced.Moreover, if the detachable sheet-pressing slice 22 is damaged, only thedetachable sheet-pressing slice 22 needs to be detached from theautomatic document feeder 2 and replaced with a new one. As aconsequence, the maintenance of the detachable sheet-pressing slice 22is very easy and speedy.

Hereinafter, the operations of the detachable sheet-pressing slice 22will be illustrated with reference to the schematic partial enlargedcross-sectional views of FIGS. 3A˜3D according to the first embodimentof the present invention.

In FIG. 3A, the detachable sheet-pressing slice 22 has been mounted onthe lower part of the sheet-feeding mechanism 21 of the automaticdocument feeder 2 for pressing the document S passing through thescanning window 40. As shown in FIG. 3B, the detachable sheet-pressingslice 22 is separated from the automatic document feeder 2. Thedetachable sheet-pressing slice 22 includes a fixing member 220 and asheet-pressing member 221. The fixing member 220 is fixed on the lowerpart of the sheet-feeding mechanism 21 and used to support thesheet-pressing member 221. The sheet-pressing member 221 imparts adownward pressing force to the document S, thereby preventing thedocument S from rising up when passing through the scanning window 40 ofthe scanning apparatus 4. As a consequence, the scanning quality of thescanning apparatus 4 will not be impaired. In an embodiment, thesheet-pressing member 221 is bonded to the fixing member 220 via adouble sided tape or other connecting means. Furthermore, the lower partof the sheet-feeding mechanism 21 of the automatic document feeder 2includes at least a retaining recess 210 for receiving the detachablesheet-pressing slice 22 therein. Depending on the numbers ofsheet-pressing members 221, the number of the retaining recesses 210 isvaried. For facilitating securely fixing the detachable sheet-pressingslice 22 in the retaining recess 210, the retaining recess 210 at thelower part of the sheet-feeding mechanism 21 and the fixing member 220of the sheet-pressing slice 22 have complementary engaging elements. Inthis embodiment, a hook structure 2100 is protruded from an inner wallof the retaining recess 210 as a first engaging element. Correspondingto the hook structure 2100, a concave structure 2200 is formed in thefixing member 220 as a second engaging element. When the detachablesheet-pressing slice 22 is inserted into the retaining recess 210 at thelower part of the sheet-feeding mechanism 21, the hook structure 2100 ofthe retaining recess 210 and the concave structure 2200 of the fixingmember 220 are engaged with each other, as is shown in FIG. 3A. Underthis circumstance, the detachable sheet-pressing slice 22 is fixed atthe lower part of the sheet-feeding mechanism 21 without detachment.

The process of refreshing the detachable sheet-pressing slice 22 will beillustrated with reference to FIGS. 3A and 3C. As shown in FIG. 3A, thefixing member 220 of the detachable sheet-pressing slice 22 is coupledwith the retaining recess 210 at the lower part of the sheet-feedingmechanism 21. In FIG. 3C, a sharp-pointed stick 5 is used to disengagethe fixing member 220 from the retaining recess 210 in order to refreshthe detachable sheet-pressing slice 22. For facilitate the user or themaintenance worker to replace the detachable sheet-pressing slice 22without detaching the sheet-feeding mechanism 21, the lower part of thesheet-feeding mechanism 21 further includes at least an ejecting channel211. Depending on the numbers of sheet-pressing members 221, the numberof the ejecting channels 211 is varied. The ejecting channel 211 iscommunicated with the retaining recess 210 and aligned with the top endof the fixing member 220, which is received in the retaining recess 210.In a case that a sharp-pointed stick 5 is penetrated through theejecting channel 211 and sustained against the fixing member 220, thetop end of the fixing member 220 is deformed or shifted, as is shown inFIG. 3C. As a consequence, the hook structure 2100 is disengaged fromthe concave structure 2200. By exerting a downward pulling force on thesheet-pressing member 221, the detachable sheet-pressing slice 22 willbe withdrawn from the retaining recess 210.

In the first embodiment of the automatic document feeder 2, thecomplementary engaging elements include the hook structure 2100protruded from an inner wall of the retaining recess 210 and the concavestructure 2200 formed in the fixing member 220. It is noted that,however, those skilled in the art will readily observe that numerousmodifications and alterations may be made while retaining the teachingsof the invention. For example, as shown in FIG. 3D, a concave structure2101 is formed in an inner wall of the retaining recess 210.Corresponding to the concave structure 2101, a hook structure 2201 isprotruded from the fixing member 220. When the hook structure 2201 isengaged with the concave structure 2101, the detachable sheet-pressingslice 22 is fixed on the lower part of the sheet-feeding mechanism 21.

FIG. 4A is a schematic partial enlarged cross-sectional viewillustrating an automatic document feeder according to a secondembodiment of the present invention. In this embodiment, the detachablesheet-pressing slice may be directly fixed in the retaining recesswithout the assistance of the fixing member. As shown in FIG. 4A, thedetachable sheet-pressing slice 32 includes a sheet-pressing member 320with a concave structure 321. Corresponding to the concave structure321, a hook structure 3100 is protruded from an inner wall of aretaining recess 310 of the sheet-feeding mechanism 31. When thesheet-pressing member 320 is inserted into the retaining recess 310, thehook structure 3100 and the concave structure 321 are engaged with eachother, as is shown in FIG. 4A. Under this circumstance, the detachablesheet-pressing slice 32 is fixed at the lower part of the sheet-feedingmechanism 31. Likewise, the lower part of the sheet-feeding mechanism 31further includes at least an ejecting channel 311, which is communicatedwith the retaining recess 310. In a case that a sharp-pointed stick (notshown) is penetrated through the ejecting channel 311 and sustainedagainst the sheet-pressing member 320, the top end of the sheet-pressingmember 320 will be deformed or shifted such that the hook structure 3100is disengaged from the concave structure 321. By exerting a downwardpulling force on the sheet-pressing member 320, the detachablesheet-pressing slice 32 may be withdrawn from the retaining recess 310.The process of withdrawing the detachable sheet-pressing slice 32 formaintenance is similar to that described in the first embodiment, and isnot redundantly described herein.

In the second embodiment of the automatic document feeder, thecomplementary engaging elements include the hook structure 3100protruded from an inner wall of the retaining recess 310 and the concavestructure 321 of the sheet-pressing member 320. By engagement of theseengaging elements, the detachable sheet-pressing slice 32 is fixed onthe lower part of the sheet-feeding mechanism 31. It is noted that,however, those skilled in the art will readily observe that numerousmodifications and alterations may be made while retaining the teachingsof the invention. For example, as shown in FIG. 4B, one or more salientstructures 322 are protruded from the sheet-pressing member 320. Thesalient structures 322 are sustained against the inner wall of the ofthe retaining recess 310, thereby further facilitating fixing thedetachable sheet-pressing slice 32 on the lower part of thesheet-feeding mechanism 31.

In the above embodiments, the concave structures 2101, 2200 and 321 areindentations. Alternatively, the concave structures 2101, 2200 and 321may be perforations for receiving corresponding hook structures therein.

While the invention has been described in terms of what is presentlyconsidered to be the most practical and preferred embodiments, it is tobe understood that the invention needs not be limited to the disclosedembodiment. On the contrary, it is intended to cover variousmodifications and similar arrangements included within the spirit andscope of the appended claims which are to be accorded with the broadestinterpretation so as to encompass all such modifications and similarstructures.

1. An automatic document feeder having a detachable sheet-pressingslice, said automatic document feeder being mounted on a scanningapparatus having a scanning window, said automatic document feedercomprising: a casing; and a sheet-feeding mechanism inside said casing,wherein said detachable sheet-pressing slice is disposed at a lower partof said sheet-feeding mechanism and around said scanning window forpressing a document passing through said scanning window.
 2. Theautomatic document feeder having a detachable sheet-pressing sliceaccording to claim 1 wherein a retaining recess is further formed atsaid lower part of said sheet-feeding mechanism for receiving saiddetachable sheet-pressing slice therein.
 3. The automatic documentfeeder having a detachable sheet-pressing slice according to claim 2wherein said detachable sheet-pressing slice includes a fixing memberand a sheet-pressing member.
 4. The automatic document feeder having adetachable sheet-pressing slice according to claim 3 wherein a hookstructure is protruded from an inner wall of said retaining recess, anda concave structure is formed in said fixing member, wherein saiddetachable sheet-pressing slice is fixed on said lower part of saidsheet-feeding mechanism when said detachable sheet-pressing slice isinserted into said retaining recess and said hook structure and saidconcave structure are engaged with each other.
 5. The automatic documentfeeder having a detachable sheet-pressing slice according to claim 4wherein an ejecting hole is further formed at said lower part of saidsheet-feeding mechanism for allowing a sharp-pointed stick to penetratetherethrough and push said fixing member, thereby disengaging said hookstructure from said concave structure.
 6. The automatic document feederhaving a detachable sheet-pressing slice according to claim 3 wherein aconcave structure is formed in an inner wall of said retaining recess,and a hook structure is protruded from said fixing member, wherein saiddetachable sheet-pressing slice is fixed on said lower part of saidsheet-feeding mechanism when said detachable sheet-pressing slice isinserted into said retaining recess and said hook structure and saidconcave structure are engaged with each other.
 7. The automatic documentfeeder having a detachable sheet-pressing slice according to claim 6wherein an ejecting hole is further formed at said lower part of saidsheet-feeding mechanism for allowing a sharp-pointed stick to penetratetherethrough and push said fixing member, thereby disengaging said hookstructure from said concave structure.
 8. The automatic document feederhaving a detachable sheet-pressing slice according to claim 2 whereinsaid detachable sheet-pressing slice is a sheet-pressing member with aconcave structure.
 9. The automatic document feeder having a detachablesheet-pressing slice according to claim 8 wherein a hook structure isprotruded from an inner wall of said retaining recess, and saiddetachable sheet-pressing slice is fixed on said lower part of saidsheet-feeding mechanism when said detachable sheet-pressing slice isinserted into said retaining recess and said hook structure and saidconcave structure are engaged with each other.
 10. The automaticdocument feeder having a detachable sheet-pressing slice according toclaim 9 wherein an ejecting hole is further formed at said lower part ofsaid sheet-feeding mechanism for allowing a sharp-pointed stick topenetrate therethrough and push said fixing member, thereby disengagingsaid hook structure from said concave structure.
 11. The automaticdocument feeder having a detachable sheet-pressing slice according toclaim 8 wherein said detachable sheet-pressing slice further one or moresalient structures to be sustained against an inner wall of saidretaining recess.
 12. An automatic document feeder having a detachablesheet-pressing slice, said automatic document feeder comprising: acasing; and a sheet-feeding mechanism inside said casing, and includinga retaining recess, a fixing member and a sheet-pressing member, whereinsaid retaining recess is disposed at a lower part of said sheet-feedingmechanism, said fixing member is received in said retaining recess, andsaid sheet-pressing member is attached on said fixing member.
 13. Theautomatic document feeder having a detachable sheet-pressing sliceaccording to claim 12 wherein a hook structure is protruded from aninner wall of said retaining recess, and a concave structure is formedin said fixing member.
 14. The automatic document feeder having adetachable sheet-pressing slice according to claim 12 wherein anejecting hole is further formed at said lower part of said sheet-feedingmechanism and communicated with said retaining recess.
 15. The automaticdocument feeder having a detachable sheet-pressing slice according toclaim 12 wherein a concave structure is formed in an inner wall of saidretaining recess, and a hook structure is protruded from said fixingmember.
 16. An automatic document feeder having a detachablesheet-pressing slice, said automatic document feeder comprising: acasing; and a sheet-feeding mechanism inside said casing, and includinga retaining recess and a sheet-pressing member, wherein said retainingrecess is disposed at a lower part of said sheet-feeding mechanism andincludes a hook structure protruded from an inner wall thereof, and saidsheet-pressing member is fixed in said retaining recess and has aconcave structure to be engaged with said hook structure.
 17. Theautomatic document feeder having a detachable sheet-pressing sliceaccording to claim 16 wherein an ejecting hole is further formed at saidlower part of said sheet-feeding mechanism and communicated with saidretaining recess.
 18. The automatic document feeder having a detachablesheet-pressing slice according to claim 16 wherein said detachablesheet-pressing slice further one or more salient structures to besustained against an inner wall of said sheet-pressing member.